Hand display devices have a long history of growth, and they already existed before the hand has been electronically controlled. Taking a familiar example, a cooking spring scale for weighing cooking material was not electronically controlled, of course. Then with the advent of the electronics age, electronic control has been playing a major role. Among all, as a basic measuring instrument, there are hand indicating testers for measuring the value of resistance and the value of voltage. Since these hand indicating testers are compact, most of them are switched over to display either the value of resistance or the value of voltage by means of single hand. Also in the resistance measuring mode, a switch for changing the range is provided, and by using the different ranges depending on the magnitude of resistance of the object to be measured, the graduations are always easy to read by means of a hand, and also the mode can be distinguished by a direction pointed by a range control knob, thus having the user read the graduation corresponding to the mode. This hand indicating tester is an early instrument which has used a single hand by switching it for displaying more than one function. In addition, as a typical example of a compact hand display device using a single hand by switching it for displaying of more than one function, there is an electronic hand display watch.
In recent years, like electronic digital watches, electronic hand analog display watches are equipped with various functions, and multi-functioning has been advancing and realized. As already commercialized products, electronic hand display watches with an alarm function, a stopwatch function, a timer function, et cetera are available.
Furthermore, there is a demand for an electronic hand display watch with various functions, but there is a limit to the number of hands in its restricted space.
An electronic hand display watch in which a single hand displays more than one function has been devised, too.
One example of a hand display device of a conventional electronic hand display watch wherein a single hand displays more than one function will be described with reference to FIGS. 9, 10 and 11.
This example is an electronic hand display watch with a stopwatch (ST) function for measuring the stopwatch 1/10-seconds, stopwatch second, stopwatch minute and stopwatch hour. For measuring stopwatch second and stopwatch minute, a stopwatch second hand and a stopwatch minute hand are provided, respectively. However, for the two functions, the stopwatch 1/10-second and stopwatch hour, a single hand is used by switchover. Such a single hand displays stopwatch 1/10-seconds when the stopwatch measuring time is in the less than 60 minute mode and hours when in the 60 minute or more mode.
Within one second after 9 hours 59 minutes and 59 seconds of the stopwatch measuring time, the display returns to 0 minutes 0 seconds 0. At this time, the hand display function is switched again to the original stopwatch 1/10-second time display. A mode hand is provided, so that after the stopwatch function has ceased, the user can correctly determine whether he or she should read the graduation as the stopwatch 1/10-second in the less than 60 minute mode or as the stopwatch hour in the 60 minute or more mode.
First, FIGS. 9 and 10 are referred to. FIG. 9 is a view showing a dial 900 and hands which form the face of a conventional electronic hand display watch, and FIG. 10 is a partially enlarged view of FIG. 9. On the dial 900, an hour hand 91, a minute hand 92 and a second hand 93 for displaying usual time are attached at the center, and around which a stopwatch second hand 94 for displaying the seconds, a stopwatch minute hand 95 for displaying the minutes, a switchover hand 96 for displaying the 1/10-seconds and the hours, and a mode hand 97 for displaying the modes are attached as smaller hands. On the peripheral portion of the dial 900 indicated by the switchover hand 96, as enlarged in FIG. 10, stopwatch 1/10-second numerals 98 necessary for reading the 1/10-seconds are arranged at the outermost position, and stopwatch hour numerals 99 necessary for reading the hours are arranged inside. At the innermost position, graduations 90 to be used for both 1/10-seconds and hours are arranged.
FIG. 11 is a block diagram of a circuit of a conventional electronic hand display watch, in which like reference numerals designate like or corresponding parts in FIG. 9, and the explanation will be omitted. In FIG. 11, a time reference source 1 produces a time reference signal P1 (32,768 Hz); a frequency dividing circuit 2 for time, which receives time reference signal P1 from the time reference source 1 for making a reference for usual time, comprises plural stages of frequency dividers and produces a signal group of time frequency division signals P2 for making a 1 Hz usual drive pulse period and pulse width; a usual time signal generating circuit 11 produces a usual time pulse P11 under a predetermined frequency division signal P2 of the frequency dividing circuit 2 for time; and a first drive circuit 16 produces a usual time driving signal P16 for usual time driving under the usual time pulse P11. The usual time driving signal P16 is applied to a first motor 21, then drives the second hand 93 which interlocks with the first motor 21, and makes the second hand 93 display the usual time, together with the minute hand 92 and the hour hand 91, which mechanically interlock with the second hand 93 by means of train mechanism.
A switching circuit 4 comprises a start/stop switch 41, a chattering preventing circuit 42 and a toggle type flip-flip 43 (operated by a rising signal applied to an input terminal T and hereinafter referred to as "T-FF"). The start/stop switch 41 interlocks with an external control member and produces a start/stop signal P41 every time the stopwatch start operation and stop operation are performed. The chattering preventing circuit 42 receives the start/stop signal P41 and produces, every stopwatch start and stop operation, a one shot signal P42 in which a mechanical chattering of the start/stop switch 41 has been eliminated. The T-FF 43 receives the one shot signal P42 at input terminal T and produces, from its output terminal Q, a switching signal P4 which is at an "L" level in the stopwatch stop condition and a "H" level in the stopwatch start condition. The level of this switching signal P4 is inverted every stopwatch start and stop operations.
A stopwatch circuit 30 comprises a stopwatch frequency dividing circuit 3, an inverter ("INV") 31 and a data type flip-flop 32 ("D-FF"). The stopwatch frequency dividing circuit 3 comprises a frequency divider of plural stages for making a reference of the stopwatch. An input terminal I of the stopwatch frequency dividing circuit 3 receives the time reference signal P1 from the time reference source 1, and a reset terminal R is controlled by a stopwatch frequency division enable signal P32 from the D-FF 32. In the stopwatch function stop state, under the stopwatch frequency division enable signal P32 at the "H" level, the frequency divider is reset, the frequency dividing operation is not performed, and the outputs of a stopwatch frequency division signal group P3 and a 16 Hz frequency division signal P34 are stopped. On the other hand, in the stopwatch function start state, under the stopwatch frequency division enable signal P32 at the "L" level, the stopwatch frequency dividing operation is performed, and the stopwatch frequency division signal group P3 for making the pulse periods and pulse widths of the stopwatch second, stopwatch minute, stopwatch 1/10-second and stopwatch hour and the 16 Hz frequency division signal P34, are produced. Also, the D-FF 32 reads in the data information at its input terminal D by the rising timing of the signal to be applied to its input terminal T. The input terminal D receives the inverted switching signal P4, the input terminal T receives the 16 Hz frequency division signal P34, and an input reset terminal R receives the switching signal P4.
A stopwatch second signal generating circuit 12 produces a 1 Hz stopwatch second pulse P12 in response to the first signal of the frequency division signal group P3 of the stopwatch frequency dividing circuit 3 in the stopwatch start state. A second drive circuit 17 which produces a stopwatch second driving signal P17 in response to the second pulse P12. The stopwatch second driving signal P17 is applied to a second motor 22 to drive the stopwatch second hand 94 which interlocks with the second motor 22 and displays stopwatch seconds.
A stopwatch minute signal generating circuit 13 produces a stopwatch minute pulse P13 at an interval of one minute in response to the second signal of the stopwatch frequency division signal group P3 of the stopwatch frequency dividing circuit 3 in the stopwatch start state. A third drive circuit 18 produces a stopwatch minute driving signal P18 in response to the minute pulse P13 in the stopwatch start state. The stopwatch minute driving signal P18 is applied to a third motor 23 to drive the stopwatch minute hand 95 which interlocks with the third motor 23 and displays stopwatch minutes.
A stopwatch 1/10-second signal generating circuit 14 produces a stopwatch 1/10-second pulse P14 of 10 Hz in response to the third signal of the stopwatch frequency division signal group P3 of the stopwatch frequency dividing circuit 3 in the stopwatch start state. A stopwatch hour signal generating circuit 15 produces a stopwatch hour pulse P15 at an interval of one hour in response to the fourth signal of the stopwatch frequency division signal group P3 of the stopwatch frequency dividing circuit 3 in the stopwatch start state.
A mode control circuit 5 comprises a base-60 counting section 51, a base-10 counting section 52 and a data type flip-flop 53 (which reads in data information at an input terminal D by the rising timing of a signal applied to an input terminal T; hereinafter called "D-FF"). When the base-60 counting section 51 counts "60" in response to the stopwatch minute pulse P13 of the stopwatch minute signal generating circuit 13, it produces a one-shot stopwatch 60-minute signal P51. In other words, the stopwatch 60-minute signal P51 is produced every 60 minutes in the stopwatch start state. When the base-10 counting section 52 counts "10" in response to the stopwatch hour pulse P15 of the stopwatch hour signal generating circuit 15, it produces a one-shot stopwatch 10-hour signal P52. That is to say, when the stopwatch measuring time comes to the stopwatch 10 hours in one second after 9 hours 59 minutes 59 seconds, the stopwatch 10-hour signal P52 controls the timing for returning the display to 0 hours 0 minutes 0 seconds and thus returning the stopwatch measuring time to the less than 60 minute mode. In the D-FF 53, an input terminal D is connected to a terminal Vdd, an input terminal T receives the stopwatch 60-minute signal P51, an input terminal R receives the stopwatch 10-hour signal P52, and from an output terminal Q, a mode switching signal P5 is produced.
More specifically, during the time between stopwatch start and 60 minutes of the stopwatch measuring time, neither the stopwatch 60-minute signal P51 nor the stopwatch 10-hour signal P52 is produced, and the mode switching signal P5 is at the "L" level, which is an initial level. When the stopwatch measuring time comes to 60 minutes, the stopwatch 60-minute signal P51 is produced, the D-FF 53 reads in the "H" level, and the mode switching signal P5 is switched from the "L" level to the "H" level. Then every 60 minutes, the stopwatch 60-minute signal P51 is produced. However, the mode switching signal P5 remains at the "H" level until the stopwatch counting time becomes 10 hours. Then, when the stopwatch counting time attains to 10 hours, the stopwatch 10-hour signal P52 and the stopwatch 60-minute signal P51 are produced at the same time, but in the D-FF 53, because of its rising operation, a resetting is always ahead, and the mode switching signal P5 is switched from the "H" level to the "L" level. Thereafter, the mode switching signal P5 repeats this operation.
Reference numeral 7 denotes a selector. When the input to a terminal C is at the "L" level, an input A is outputted from a terminal Q, and when the input to the terminal C is at the "H" level, an input B is outputted from the terminal Q. An input terminal A of the selector 7 receives the stopwatch 1/10-second pulse P14 from the stopwatch 1/10-second signal generating circuit 14, an input terminal B receives the stopwatch hour pulse P15 from the stopwatch hour signal generating circuit 15, and the control terminal C is controlled by the mode switching signal P5 of the mode control circuit 5. In the less than 60 minute mode of the stopwatch measuring time, the stopwatch 1/10-second pulse P14 is produced, and in the 60 minute or more mode, the stopwatch hour pulse P15 is produced.
A fourth drive circuit 19 produces a common driving signal P19 for driving both the stopwatch 1/10-second and the stopwatch hour in response to output signal of the selector 7. The common driving signal P19 is applied to a fourth motor 24 for driving the switchover hand 96 which interlocks with the fourth motor 24.
A mode signal generating circuit 6 receives the fifth signal of the stopwatch frequency division signal group P3 from the stopwatch frequency dividing circuit 3 and the mode switching signal P5 from the mode control circuit 5 and outputs a mode pulse P6 for a mode display pursuant to rising or falling timing of the mode switching signal P5. In other words, whenever the mode is changed, the mode pulse P6 is outputted.
A fifth drive circuit 20 produces a mode display driving signal P20 in response to the mode pulse P6. The mode display driving signal P20 is applied to a fifth motor 25 to drive the mode hand 97 which interlocks with the fifth motor 25 for mode display.
Next, the operation of the electronic hand display watch having the above structure will be described. The circuit of the usual time system of the hour hand 91, the minute hand 92 and the second hand 93 attached in the center of the dial 900 always operate to display the usual time. As for the stopwatch function, in the stopwatch stop state, since the switching signal P4 from the switching circuit 4 is at the "L" level, the frequency enabling signal P32 is at the "H" level, and therefore, the stopwatch frequency dividing circuit 3 does not perform the frequency dividing operation, and the stopwatch frequency division signal P3 is not produced. Thus, the stopwatch system circuit does not operate. As a result, the stopwatch second hand 94, the stopwatch minute hand 95, the switchover hand 96 and the mode hand 97 remain stopped. When the stopwatch start operation is initiated by means of external control member, the switching signal P4 is changed from the "L" level to the "H" level, the D-FF 32 is reset, and the stopwatch frequency division signal P32 is changed from the "H" level to the "L" level. The stopwatch frequency dividing circuit 3 starts the frequency dividing operation to produce the stopwatch frequency division signal group P3. In response to the stopwatch frequency division signal group P3, the stopwatch second signal generating circuit 12, the stopwatch minute signal generating circuit 13, the stopwatch 1/10-second signal generating circuit 14 and the stopwatch hour signal generating circuit 15 operate. In the less than 60 minute mode of the stopwatch measuring time, the mode switching signal P5 is at the "L" level, the stopwatch 1/10-second pulse P14 in the selector 7, is selected and produced, the switchover hand 96 is driven at 10 Hz in response to the stopwatch 1/10-second pulse P14, and indicates the 1/10-second display, and the stopwatch minute hand 95, the stopwatch second hand 94 and the switchover hand 96 display the stopwatch minute, second and 1/10 second. Also, in this mode, the mode hand 97 points to "1/10 SEC" to indicate that the switchover hand 96 shows 1/10 seconds. When the stopwatch measuring time comes to 60 minutes, the mode switching signal P5 of the mode control circuit 5 is changed from the "L" level to the "H" level, and in a moment of time, the mode pulse P6 is outputted from the mode signal generating circuit 6, and the mode hand 97 is driven accordingly to indicate "HOUR" message.
On the other hand, in the selector 7, by the mode switching signal P5 at the "H" level, the stopwatch hour pulse P15 has been selected and produced. In response to the stopwatch hour pulse P15, the switchover hand 96 is driven at an interval of one hour and shows the stopwatch hour. The stopwatch minute hand 95, the stopwatch second hand 94 and the switchover hand 96 show the stopwatch hour, minute and second, respectively. Also in the mode for 60 minutes or more of the stopwatch measuring time, the mode hand 97 points to "HOUR" to indicate that the switchover hand 96 shows the stopwatch hour.
When the stopwatch measuring time advances and comes to 10 hours, the mode switching signal P5 returns from the "H" level to the "L" level. In a moment of time, from the mode signal generating circuit 6, the mode pulse P6 is outputted, and the mode hand 97 is driven accordingly and points to "1/10 SEC". That is, the stopwatch measuring time returns to the less than 60 minute mode, the switchover hand 96 returns to the stopwatch 1/10-second again, and the stopwatch minute hand 95, the stopwatch second hand 94 and switchover hand 96 show the stopwatch minute, second and 1/10 second. Also, in either mode, the external control member permits the stopwatch stop operation, which causes the switching signal P4 to change from the "H" level to the "L" level, and by the timing of the 16 Hz frequency division signal P34, the D-FF 32 changes to the "H" level. Thus, in the absence of the driving signal, the stopwatch frequency dividing circuit 3 stops the frequency dividing operation, and the stopwatch hand stops accordingly. Therefore, the measured stopwatch time can be read.
As mentioned above, in the conventional electronic hand display watch, the graduations 90 indicated by the switchover hand 96 for changeably displaying the two functions of the stopwatch 1/10-second function and the stopwatch hour function are used in common to the stopwatch 1/10-second and the stopwatch hour. Therefore, the user cannot tell only by the switchover hand 96 whether he or she should read the numerals 98 for the stopwatch 1/10-second or the numerals 99 for the stopwatch hour. However, the mode hand 97 can show the user how to read the numerals for graduations 90 indicated by the switchover hand 96; In other words, when the mode hand 97 points to "1/10 SEC" in the mode for less than 60 minutes of the stopwatch measuring time, the user reads the numerals 98 for the stopwatch 1/10-second. When the mode hand 97 points to "HOUR" in the mode for 60 minutes or more of the stopwatch measuring time, the user reads the numerals 99 for the stopwatch hour.
Thus, in the conventional electronic hand display watch, the graduations 90 and the stopwatch 1/10-second numerals and the stopwatch-hour numerals 99 to be indicated by the switchover hand 96 for switching two functions occupy the same positions. Therefore, without reading the mode hand 97 which is a reading discrimination display means, the user cannot determine whether he should read the numerals 98 for the stopwatch 1/10-second or the numerals 99 for the stopwatch-hour. However, since the prices of watches are decreased in the recent market, even multifunction watches are suffering from a severe cost-down competition and their cost-down is necessary, and there is a big problem of cost-up caused by the mode hand 97, which is merely a display means for reading discrimination, and its driving control.
Also, in other type of hand display instruments, the cost of a hand display tester is raised because of its range control for indicating modes as reading discrimination display means.